The present invention relates to a side airbag apparatus accommodated in a vehicle seat.
Conventional side airbag apparatuses are provided in, for example, a side portion of a vehicle seat back located on the vehicle outer side. When a side collision of a vehicle occurs, the airbag projects from a side portion of a seat back on the vehicle outer side and is inflated and deployed in a space between an occupant and a side body including a door, thereby protecting region of the occupant's body including the thorax and the head. Japanese Laid-Open Patent Publication No. 2001-114060 discloses such a side airbag apparatus. This airbag apparatus includes an airbag unit, which includes an airbag and an inflator, and a case storing the airbag. The case is formed by a base plate covering a part of the airbag located on the vehicle inner side and a back guide covering the rear portion of the airbag. The airbag unit is installed by fixing the base plate, which is a part of the case, to the frame of the seat back with bolts and nuts. The airbag unit is thus retained in the seat back.
The airbag contained in the airbag unit is designed to be arranged beside a region of an occupant's body including the thorax and the head. The airbag thus has an elongated shape extending in the up-down direction. Accordingly, the case, which accommodates the elongated airbag, is large, which increases the size of the side airbag apparatus. In this regard, conventional side airbag apparatuses have been desired to be improved.
Also, conventional side airbag apparatuses have room for improvement in the following aspects. For example, an occupant might unintentionally push a side airbag apparatus by putting a hand on the seat back when getting in or out of the vehicle. In such a case, the conventional airbag apparatus described above may be felt by the occupant, who in turn may be disturbed by the feel.